25-05-2012, 03:30 PM
Drilling AND Related Processes
drilling.ppt (Size: 1.86 MB / Downloads: 77)
Drilling & Related Hole Making Processes
Basic hole making processes account for approximately 50-70% of all the metal removal processes utilized today.
Holes
Casting
Sand, die, molding
Punching
Machining,
Drilling, milling, EDM, AWJ, etc.
Burning
Processes
Standard hole making processes include:
Drilling - Drilling is the process of producing or enlarging a hole. This is accomplished by rotating the tool and/or workpiece.
Reaming - Enlarging an existing hole with a multi-edged tool (reamer) for dimensional accuracy and/or surface finish
Spot facing - Smoothing, squaring, and/or flattening a surface
Parts of a Twist Drill
Shank - This is the portion which is “clamped” to provide the drive. Straight shank for drill up to ½”. Shank is equal to body diameter. Above ½”, shank can be tapered or reduced.
Body
Flutes - Helical grooves cut around the body which form the cutting edges
Allow coolant to flow to the cutting edge
Allow chips to be withdrawn
Drill Presses
Upright Drill Press
Larger than the sensitive
Can be equipped with a gearbox and variable speed head
Hand and automatic feed mechanism
Automatic coolant system
Table can move on a rack and pinion system